Abstract: Taking a rotary atomizer in a deacidification tower as an object, based on VOF model and DPM models, the primary crushing process of lime slurry and the particle size distribution characteristics after atomization were simulated by Fluent, and the influences of the rotating speed of atomizing disk,single nozzle, parallel double/triple nozzles and nozzle spacing on the primary crushing and particle size distribution of nozzle jet were analyzed. The results show that the droplet breakup under the condition of high-speed jet is mainly caused by the superposition of circumferential surface waves and axial waves,and presents a symmetrical shape with respect to the main flow. The polymerization range of multi-hole jet is proportional to the nozzle spacing, and increasing the number of nozzles leads to the early polymerization of jet. Increasing the rotating speed of atomizing disk, nozzle spacing and nozzles is benefit for reducing the average diameter of atomized droplets. A simple linear correlation of average diameter of droplets and nozzle spacing is obtained for the multi-nozzles.